forked from mirrors/gecko-dev
33a9e6d050
<!-- Please describe your changes on the following line: --> Before this PR, every object reflected in CSSOM is in `Arc<RwLock<_>>` to enable safe (synchronized) mutable aliasing. Acquiring all these locks has significant cost during selector matching: * https://bugzilla.mozilla.org/show_bug.cgi?id=1311469 * https://bugzilla.mozilla.org/show_bug.cgi?id=1335941 * https://bugzilla.mozilla.org/show_bug.cgi?id=1339703 This PR introduce a mechanism to protect many objects with the same `RwLock` that only needs to be acquired once. In Stylo, there is one such lock per process (in a `lazy_static`), used for everything. I non-Stylo Servo, I originally intended to have one such lock per document (for author-origin stylesheets, and one per process for user-agent and user sytlesheets since they’re shared across documents, and never mutated anyway). However I failed to have the same document-specific (or pipeline-specific) `Arc` reachable from both `Document` nodes and `LayoutThread`. Recursively following callers lead me to include this `Arc` in `UnprivilegedPipelineContent`, but that needs to be serializable. So there is a second process-wide lock. This was previously #15998, closed accidentally. --- <!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: --> - [x] `./mach build -d` does not report any errors - [x] `./mach test-tidy` does not report any errors - [ ] These changes fix #__ (github issue number if applicable). <!-- Either: --> - [ ] There are tests for these changes OR - [ ] These changes do not require tests because _____ <!-- Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process. --> Source-Repo: https://github.com/servo/servo Source-Revision: bb54f0a429de0e8b8861f8071b6cf82f73622664 --HG-- extra : subtree_source : https%3A//hg.mozilla.org/projects/converted-servo-linear extra : subtree_revision : 851230e57ac8775707df5f0f103be5feac81fc41
598 lines
26 KiB
Rust
598 lines
26 KiB
Rust
/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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//! The generated content assignment phase.
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//!
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//! This phase handles CSS counters, quotes, and ordered lists per CSS § 12.3-12.5. It cannot be
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//! done in parallel and is therefore a sequential pass that runs on as little of the flow tree
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//! as possible.
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use context::{LayoutContext, with_thread_local_font_context};
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use flow::{self, AFFECTS_COUNTERS, Flow, HAS_COUNTER_AFFECTING_CHILDREN, ImmutableFlowUtils};
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use flow::InorderFlowTraversal;
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use fragment::{Fragment, GeneratedContentInfo, SpecificFragmentInfo, UnscannedTextFragmentInfo};
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use gfx::display_list::OpaqueNode;
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use script_layout_interface::wrapper_traits::PseudoElementType;
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use smallvec::SmallVec;
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use std::collections::{HashMap, LinkedList};
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use std::sync::Arc;
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use style::computed_values::{display, list_style_type};
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use style::computed_values::content::ContentItem;
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use style::properties::ServoComputedValues;
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use style::selector_parser::RestyleDamage;
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use style::servo::restyle_damage::RESOLVE_GENERATED_CONTENT;
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use text::TextRunScanner;
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// Decimal styles per CSS-COUNTER-STYLES § 6.1:
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static DECIMAL: [char; 10] = [ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' ];
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// TODO(pcwalton): `decimal-leading-zero`
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static ARABIC_INDIC: [char; 10] = [ '٠', '١', '٢', '٣', '٤', '٥', '٦', '٧', '٨', '٩' ];
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// TODO(pcwalton): `armenian`, `upper-armenian`, `lower-armenian`
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static BENGALI: [char; 10] = [ '০', '১', '২', '৩', '৪', '৫', '৬', '৭', '৮', '৯' ];
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static CAMBODIAN: [char; 10] = [ '០', '១', '២', '៣', '៤', '៥', '៦', '៧', '៨', '៩' ];
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// TODO(pcwalton): Suffix for CJK decimal.
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static CJK_DECIMAL: [char; 10] = [ '〇', '一', '二', '三', '四', '五', '六', '七', '八', '九' ];
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static DEVANAGARI: [char; 10] = [ '०', '१', '२', '३', '४', '५', '६', '७', '८', '९' ];
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// TODO(pcwalton): `georgian`
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static GUJARATI: [char; 10] = ['૦', '૧', '૨', '૩', '૪', '૫', '૬', '૭', '૮', '૯'];
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static GURMUKHI: [char; 10] = ['੦', '੧', '੨', '੩', '੪', '੫', '੬', '੭', '੮', '੯'];
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// TODO(pcwalton): `hebrew`
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static KANNADA: [char; 10] = ['೦', '೧', '೨', '೩', '೪', '೫', '೬', '೭', '೮', '೯'];
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static LAO: [char; 10] = ['໐', '໑', '໒', '໓', '໔', '໕', '໖', '໗', '໘', '໙'];
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static MALAYALAM: [char; 10] = ['൦', '൧', '൨', '൩', '൪', '൫', '൬', '൭', '൮', '൯'];
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static MONGOLIAN: [char; 10] = ['᠐', '᠑', '᠒', '᠓', '᠔', '᠕', '᠖', '᠗', '᠘', '᠙'];
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static MYANMAR: [char; 10] = ['၀', '၁', '၂', '၃', '၄', '၅', '၆', '၇', '၈', '၉'];
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static ORIYA: [char; 10] = ['୦', '୧', '୨', '୩', '୪', '୫', '୬', '୭', '୮', '୯'];
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static PERSIAN: [char; 10] = ['۰', '۱', '۲', '۳', '۴', '۵', '۶', '۷', '۸', '۹'];
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// TODO(pcwalton): `lower-roman`, `upper-roman`
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static TELUGU: [char; 10] = ['౦', '౧', '౨', '౩', '౪', '౫', '౬', '౭', '౮', '౯'];
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static THAI: [char; 10] = ['๐', '๑', '๒', '๓', '๔', '๕', '๖', '๗', '๘', '๙'];
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static TIBETAN: [char; 10] = ['༠', '༡', '༢', '༣', '༤', '༥', '༦', '༧', '༨', '༩'];
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// Alphabetic styles per CSS-COUNTER-STYLES § 6.2:
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static LOWER_ALPHA: [char; 26] = [
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'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's',
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't', 'u', 'v', 'w', 'x', 'y', 'z'
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];
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static UPPER_ALPHA: [char; 26] = [
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'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S',
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'T', 'U', 'V', 'W', 'X', 'Y', 'Z'
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];
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static CJK_EARTHLY_BRANCH: [char; 12] = [
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'子', '丑', '寅', '卯', '辰', '巳', '午', '未', '申', '酉', '戌', '亥'
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];
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static CJK_HEAVENLY_STEM: [char; 10] = [
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'甲', '乙', '丙', '丁', '戊', '己', '庚', '辛', '壬', '癸'
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];
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static LOWER_GREEK: [char; 24] = [
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'α', 'β', 'γ', 'δ', 'ε', 'ζ', 'η', 'θ', 'ι', 'κ', 'λ', 'μ', 'ν', 'ξ', 'ο', 'π', 'ρ', 'σ', 'τ',
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'υ', 'φ', 'χ', 'ψ', 'ω'
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];
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static HIRAGANA: [char; 48] = [
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'あ', 'い', 'う', 'え', 'お', 'か', 'き', 'く', 'け', 'こ', 'さ', 'し', 'す', 'せ', 'そ',
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'た', 'ち', 'つ', 'て', 'と', 'な', 'に', 'ぬ', 'ね', 'の', 'は', 'ひ', 'ふ', 'へ', 'ほ',
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'ま', 'み', 'む', 'め', 'も', 'や', 'ゆ', 'よ', 'ら', 'り', 'る', 'れ', 'ろ',
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'わ', 'ゐ', 'ゑ', 'を', 'ん'
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];
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static HIRAGANA_IROHA: [char; 47] = [
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'い', 'ろ', 'は', 'に', 'ほ', 'へ', 'と', 'ち', 'り', 'ぬ', 'る', 'を', 'わ', 'か', 'よ',
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'た', 'れ', 'そ', 'つ', 'ね', 'な', 'ら', 'む', 'う', 'ゐ', 'の', 'お', 'く', 'や', 'ま',
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'け', 'ふ', 'こ', 'え', 'て', 'あ', 'さ', 'き', 'ゆ', 'め', 'み', 'し', 'ゑ',
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'ひ', 'も', 'せ', 'す'
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];
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static KATAKANA: [char; 48] = [
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'ア', 'イ', 'ウ', 'エ', 'オ', 'カ', 'キ', 'ク', 'ケ', 'コ', 'サ', 'シ', 'ス', 'セ', 'ソ',
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'タ', 'チ', 'ツ', 'テ', 'ト', 'ナ', 'ニ', 'ヌ', 'ネ', 'ノ', 'ハ', 'ヒ', 'フ', 'ヘ', 'ホ',
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'マ', 'ミ', 'ム', 'メ', 'モ', 'ヤ', 'ユ', 'ヨ', 'ラ', 'リ', 'ル', 'レ', 'ロ',
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'ワ', 'ヰ', 'ヱ', 'ヲ', 'ン'
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];
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static KATAKANA_IROHA: [char; 47] = [
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'イ', 'ロ', 'ハ', 'ニ', 'ホ', 'ヘ', 'ト', 'チ', 'リ', 'ヌ', 'ル', 'ヲ', 'ワ', 'カ', 'ヨ',
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'タ', 'レ', 'ソ', 'ツ', 'ネ', 'ナ', 'ラ', 'ム', 'ウ', 'ヰ', 'ノ', 'オ', 'ク', 'ヤ', 'マ',
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'ケ', 'フ', 'コ', 'エ', 'テ', 'ア', 'サ', 'キ', 'ユ', 'メ', 'ミ', 'シ', 'ヱ',
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'ヒ', 'モ', 'セ', 'ス'
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];
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/// The generated content resolution traversal.
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pub struct ResolveGeneratedContent<'a> {
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/// The layout context.
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layout_context: &'a LayoutContext<'a>,
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/// The counter representing an ordered list item.
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list_item: Counter,
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/// Named CSS counters.
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counters: HashMap<String, Counter>,
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/// The level of quote nesting.
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quote: u32,
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}
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impl<'a> ResolveGeneratedContent<'a> {
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/// Creates a new generated content resolution traversal.
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pub fn new(layout_context: &'a LayoutContext) -> ResolveGeneratedContent<'a> {
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ResolveGeneratedContent {
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layout_context: layout_context,
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list_item: Counter::new(),
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counters: HashMap::new(),
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quote: 0,
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}
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}
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}
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impl<'a> InorderFlowTraversal for ResolveGeneratedContent<'a> {
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#[inline]
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fn process(&mut self, flow: &mut Flow, level: u32) {
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let mut mutator = ResolveGeneratedContentFragmentMutator {
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traversal: self,
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level: level,
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is_block: flow.is_block_like(),
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incremented: false,
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};
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flow.mutate_fragments(&mut |fragment| mutator.mutate_fragment(fragment))
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}
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#[inline]
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fn should_process(&mut self, flow: &mut Flow) -> bool {
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flow::base(flow).restyle_damage.intersects(RESOLVE_GENERATED_CONTENT) ||
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flow::base(flow).flags.intersects(AFFECTS_COUNTERS | HAS_COUNTER_AFFECTING_CHILDREN)
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}
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}
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/// The object that mutates the generated content fragments.
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struct ResolveGeneratedContentFragmentMutator<'a,'b:'a> {
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/// The traversal.
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traversal: &'a mut ResolveGeneratedContent<'b>,
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/// The level we're at in the flow tree.
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level: u32,
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/// Whether this flow is a block flow.
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is_block: bool,
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/// Whether we've incremented the counter yet.
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incremented: bool,
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}
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impl<'a,'b> ResolveGeneratedContentFragmentMutator<'a,'b> {
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fn mutate_fragment(&mut self, fragment: &mut Fragment) {
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// We only reset and/or increment counters once per flow. This avoids double-incrementing
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// counters on list items (once for the main fragment and once for the marker).
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if !self.incremented {
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self.reset_and_increment_counters_as_necessary(fragment);
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}
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let mut list_style_type = fragment.style().get_list().list_style_type;
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if fragment.style().get_box().display != display::T::list_item {
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list_style_type = list_style_type::T::none
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}
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let mut new_info = None;
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{
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let info =
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if let SpecificFragmentInfo::GeneratedContent(ref mut info) = fragment.specific {
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info
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} else {
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return
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};
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match **info {
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GeneratedContentInfo::ListItem => {
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new_info = self.traversal.list_item.render(self.traversal.layout_context,
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fragment.node,
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fragment.pseudo.clone(),
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fragment.style.clone(),
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list_style_type,
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RenderingMode::Suffix(".\u{00a0}"))
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}
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GeneratedContentInfo::Empty |
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GeneratedContentInfo::ContentItem(ContentItem::String(_)) => {
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// Nothing to do here.
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}
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GeneratedContentInfo::ContentItem(ContentItem::Counter(ref counter_name,
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counter_style)) => {
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let temporary_counter = Counter::new();
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let counter = self.traversal
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.counters
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.get(&*counter_name)
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.unwrap_or(&temporary_counter);
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new_info = counter.render(self.traversal.layout_context,
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fragment.node,
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fragment.pseudo.clone(),
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fragment.style.clone(),
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counter_style,
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RenderingMode::Plain)
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}
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GeneratedContentInfo::ContentItem(ContentItem::Counters(ref counter_name,
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ref separator,
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counter_style)) => {
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let temporary_counter = Counter::new();
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let counter = self.traversal
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.counters
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.get(&*counter_name)
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.unwrap_or(&temporary_counter);
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new_info = counter.render(self.traversal.layout_context,
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fragment.node,
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fragment.pseudo,
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fragment.style.clone(),
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counter_style,
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RenderingMode::All(&separator));
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}
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GeneratedContentInfo::ContentItem(ContentItem::OpenQuote) => {
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new_info = render_text(self.traversal.layout_context,
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fragment.node,
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fragment.pseudo,
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fragment.style.clone(),
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self.quote(&*fragment.style, false));
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self.traversal.quote += 1
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}
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GeneratedContentInfo::ContentItem(ContentItem::CloseQuote) => {
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if self.traversal.quote >= 1 {
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self.traversal.quote -= 1
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}
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new_info = render_text(self.traversal.layout_context,
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fragment.node,
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fragment.pseudo,
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fragment.style.clone(),
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self.quote(&*fragment.style, true));
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}
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GeneratedContentInfo::ContentItem(ContentItem::NoOpenQuote) => {
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self.traversal.quote += 1
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}
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GeneratedContentInfo::ContentItem(ContentItem::NoCloseQuote) => {
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if self.traversal.quote >= 1 {
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self.traversal.quote -= 1
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}
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}
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}
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};
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fragment.specific = match new_info {
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Some(new_info) => new_info,
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// If the fragment did not generate any content, replace it with a no-op placeholder
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// so that it isn't processed again on the next layout. FIXME (mbrubeck): When
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// processing an inline flow, this traversal should be allowed to insert or remove
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// fragments. Then we can just remove these fragments rather than adding placeholders.
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None => SpecificFragmentInfo::GeneratedContent(box GeneratedContentInfo::Empty)
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};
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}
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fn reset_and_increment_counters_as_necessary(&mut self, fragment: &mut Fragment) {
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let mut list_style_type = fragment.style().get_list().list_style_type;
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if !self.is_block || fragment.style().get_box().display != display::T::list_item {
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list_style_type = list_style_type::T::none
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}
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match list_style_type {
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list_style_type::T::disc | list_style_type::T::none | list_style_type::T::circle |
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list_style_type::T::square | list_style_type::T::disclosure_open |
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list_style_type::T::disclosure_closed => {}
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_ => self.traversal.list_item.increment(self.level, 1),
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}
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// Truncate down counters.
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for (_, counter) in &mut self.traversal.counters {
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counter.truncate_to_level(self.level);
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}
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self.traversal.list_item.truncate_to_level(self.level);
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for &(ref counter_name, value) in &fragment.style().get_counters().counter_reset.0 {
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if let Some(ref mut counter) = self.traversal.counters.get_mut(counter_name) {
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counter.reset(self.level, value);
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continue
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}
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let mut counter = Counter::new();
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counter.reset(self.level, value);
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self.traversal.counters.insert((*counter_name).clone(), counter);
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}
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for &(ref counter_name, value) in &fragment.style().get_counters().counter_increment.0 {
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if let Some(ref mut counter) = self.traversal.counters.get_mut(counter_name) {
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counter.increment(self.level, value);
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continue
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}
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let mut counter = Counter::new();
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counter.increment(self.level, value);
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self.traversal.counters.insert((*counter_name).clone(), counter);
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}
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self.incremented = true
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}
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fn quote(&self, style: &ServoComputedValues, close: bool) -> String {
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let quotes = &style.get_list().quotes;
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if quotes.0.is_empty() {
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return String::new()
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}
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let &(ref open_quote, ref close_quote) =
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if self.traversal.quote as usize >= quotes.0.len() {
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quotes.0.last().unwrap()
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} else {
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"es.0[self.traversal.quote as usize]
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};
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if close {
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close_quote.clone()
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} else {
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open_quote.clone()
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}
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}
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}
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/// A counter per CSS 2.1 § 12.4.
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struct Counter {
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/// The values at each level.
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values: Vec<CounterValue>,
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}
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impl Counter {
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fn new() -> Counter {
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Counter {
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values: Vec::new(),
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}
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}
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fn reset(&mut self, level: u32, value: i32) {
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// Do we have an instance of the counter at this level? If so, just mutate it.
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if let Some(ref mut existing_value) = self.values.last_mut() {
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if level == existing_value.level {
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existing_value.value = value;
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return
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}
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}
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// Otherwise, push a new instance of the counter.
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self.values.push(CounterValue {
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level: level,
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value: value,
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})
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}
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fn truncate_to_level(&mut self, level: u32) {
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if let Some(position) = self.values.iter().position(|value| value.level > level) {
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self.values.truncate(position)
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}
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}
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fn increment(&mut self, level: u32, amount: i32) {
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if let Some(ref mut value) = self.values.last_mut() {
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value.value += amount;
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return
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}
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self.values.push(CounterValue {
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level: level,
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value: amount,
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})
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}
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fn render(&self,
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layout_context: &LayoutContext,
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node: OpaqueNode,
|
||
pseudo: PseudoElementType<()>,
|
||
style: Arc<ServoComputedValues>,
|
||
list_style_type: list_style_type::T,
|
||
mode: RenderingMode)
|
||
-> Option<SpecificFragmentInfo> {
|
||
let mut string = String::new();
|
||
match mode {
|
||
RenderingMode::Plain => {
|
||
let value = match self.values.last() {
|
||
Some(ref value) => value.value,
|
||
None => 0,
|
||
};
|
||
push_representation(value, list_style_type, &mut string)
|
||
}
|
||
RenderingMode::Suffix(suffix) => {
|
||
let value = match self.values.last() {
|
||
Some(ref value) => value.value,
|
||
None => 0,
|
||
};
|
||
push_representation(value, list_style_type, &mut string);
|
||
string.push_str(suffix)
|
||
}
|
||
RenderingMode::All(separator) => {
|
||
let mut first = true;
|
||
for value in &self.values {
|
||
if !first {
|
||
string.push_str(separator)
|
||
}
|
||
first = false;
|
||
push_representation(value.value, list_style_type, &mut string)
|
||
}
|
||
}
|
||
}
|
||
|
||
if string.is_empty() {
|
||
None
|
||
} else {
|
||
render_text(layout_context, node, pseudo, style, string)
|
||
}
|
||
}
|
||
}
|
||
|
||
/// How a counter value is to be rendered.
|
||
enum RenderingMode<'a> {
|
||
/// The innermost counter value is rendered with no extra decoration.
|
||
Plain,
|
||
/// The innermost counter value is rendered with the given string suffix.
|
||
Suffix(&'a str),
|
||
/// All values of the counter are rendered with the given separator string between them.
|
||
All(&'a str),
|
||
}
|
||
|
||
/// The value of a counter at a given level.
|
||
struct CounterValue {
|
||
/// The level of the flow tree that this corresponds to.
|
||
level: u32,
|
||
/// The value of the counter at this level.
|
||
value: i32,
|
||
}
|
||
|
||
/// Creates fragment info for a literal string.
|
||
fn render_text(layout_context: &LayoutContext,
|
||
node: OpaqueNode,
|
||
pseudo: PseudoElementType<()>,
|
||
style: Arc<ServoComputedValues>,
|
||
string: String)
|
||
-> Option<SpecificFragmentInfo> {
|
||
let mut fragments = LinkedList::new();
|
||
let info = SpecificFragmentInfo::UnscannedText(
|
||
box UnscannedTextFragmentInfo::new(string, None));
|
||
fragments.push_back(Fragment::from_opaque_node_and_style(node,
|
||
pseudo,
|
||
style.clone(),
|
||
style,
|
||
RestyleDamage::rebuild_and_reflow(),
|
||
info));
|
||
// FIXME(pcwalton): This should properly handle multiple marker fragments. This could happen
|
||
// due to text run splitting.
|
||
let fragments = with_thread_local_font_context(layout_context, |font_context| {
|
||
TextRunScanner::new().scan_for_runs(font_context, fragments)
|
||
});
|
||
if fragments.is_empty() {
|
||
None
|
||
} else {
|
||
Some(fragments.fragments.into_iter().next().unwrap().specific)
|
||
}
|
||
}
|
||
|
||
/// Appends string that represents the value rendered using the system appropriate for the given
|
||
/// `list-style-type` onto the given string.
|
||
fn push_representation(value: i32, list_style_type: list_style_type::T, accumulator: &mut String) {
|
||
match list_style_type {
|
||
list_style_type::T::none => {}
|
||
list_style_type::T::disc |
|
||
list_style_type::T::circle |
|
||
list_style_type::T::square |
|
||
list_style_type::T::disclosure_open |
|
||
list_style_type::T::disclosure_closed => {
|
||
accumulator.push(static_representation(list_style_type))
|
||
}
|
||
list_style_type::T::decimal => push_numeric_representation(value, &DECIMAL, accumulator),
|
||
list_style_type::T::arabic_indic => {
|
||
push_numeric_representation(value, &ARABIC_INDIC, accumulator)
|
||
}
|
||
list_style_type::T::bengali => push_numeric_representation(value, &BENGALI, accumulator),
|
||
list_style_type::T::cambodian | list_style_type::T::khmer => {
|
||
push_numeric_representation(value, &CAMBODIAN, accumulator)
|
||
}
|
||
list_style_type::T::cjk_decimal => {
|
||
push_numeric_representation(value, &CJK_DECIMAL, accumulator)
|
||
}
|
||
list_style_type::T::devanagari => {
|
||
push_numeric_representation(value, &DEVANAGARI, accumulator)
|
||
}
|
||
list_style_type::T::gujarati => push_numeric_representation(value, &GUJARATI, accumulator),
|
||
list_style_type::T::gurmukhi => push_numeric_representation(value, &GURMUKHI, accumulator),
|
||
list_style_type::T::kannada => push_numeric_representation(value, &KANNADA, accumulator),
|
||
list_style_type::T::lao => push_numeric_representation(value, &LAO, accumulator),
|
||
list_style_type::T::malayalam => {
|
||
push_numeric_representation(value, &MALAYALAM, accumulator)
|
||
}
|
||
list_style_type::T::mongolian => {
|
||
push_numeric_representation(value, &MONGOLIAN, accumulator)
|
||
}
|
||
list_style_type::T::myanmar => push_numeric_representation(value, &MYANMAR, accumulator),
|
||
list_style_type::T::oriya => push_numeric_representation(value, &ORIYA, accumulator),
|
||
list_style_type::T::persian => push_numeric_representation(value, &PERSIAN, accumulator),
|
||
list_style_type::T::telugu => push_numeric_representation(value, &TELUGU, accumulator),
|
||
list_style_type::T::thai => push_numeric_representation(value, &THAI, accumulator),
|
||
list_style_type::T::tibetan => push_numeric_representation(value, &TIBETAN, accumulator),
|
||
list_style_type::T::lower_alpha => {
|
||
push_alphabetic_representation(value, &LOWER_ALPHA, accumulator)
|
||
}
|
||
list_style_type::T::upper_alpha => {
|
||
push_alphabetic_representation(value, &UPPER_ALPHA, accumulator)
|
||
}
|
||
list_style_type::T::cjk_earthly_branch => {
|
||
push_alphabetic_representation(value, &CJK_EARTHLY_BRANCH, accumulator)
|
||
}
|
||
list_style_type::T::cjk_heavenly_stem => {
|
||
push_alphabetic_representation(value, &CJK_HEAVENLY_STEM, accumulator)
|
||
}
|
||
list_style_type::T::lower_greek => {
|
||
push_alphabetic_representation(value, &LOWER_GREEK, accumulator)
|
||
}
|
||
list_style_type::T::hiragana => {
|
||
push_alphabetic_representation(value, &HIRAGANA, accumulator)
|
||
}
|
||
list_style_type::T::hiragana_iroha => {
|
||
push_alphabetic_representation(value, &HIRAGANA_IROHA, accumulator)
|
||
}
|
||
list_style_type::T::katakana => {
|
||
push_alphabetic_representation(value, &KATAKANA, accumulator)
|
||
}
|
||
list_style_type::T::katakana_iroha => {
|
||
push_alphabetic_representation(value, &KATAKANA_IROHA, accumulator)
|
||
}
|
||
}
|
||
}
|
||
|
||
/// Returns the static character that represents the value rendered using the given list-style, if
|
||
/// possible.
|
||
pub fn static_representation(list_style_type: list_style_type::T) -> char {
|
||
match list_style_type {
|
||
list_style_type::T::disc => '•',
|
||
list_style_type::T::circle => '◦',
|
||
list_style_type::T::square => '▪',
|
||
list_style_type::T::disclosure_open => '▾',
|
||
list_style_type::T::disclosure_closed => '‣',
|
||
_ => panic!("No static representation for this list-style-type!"),
|
||
}
|
||
}
|
||
|
||
/// Pushes the string that represents the value rendered using the given *alphabetic system* onto
|
||
/// the accumulator per CSS-COUNTER-STYLES § 3.1.4.
|
||
fn push_alphabetic_representation(value: i32, system: &[char], accumulator: &mut String) {
|
||
let mut abs_value = handle_negative_value(value, accumulator);
|
||
|
||
let mut string: SmallVec<[char; 8]> = SmallVec::new();
|
||
while abs_value != 0 {
|
||
// Step 1.
|
||
abs_value = abs_value - 1;
|
||
// Step 2.
|
||
string.push(system[abs_value % system.len()]);
|
||
// Step 3.
|
||
abs_value = abs_value / system.len();
|
||
}
|
||
|
||
accumulator.extend(string.iter().cloned().rev())
|
||
}
|
||
|
||
/// Pushes the string that represents the value rendered using the given *numeric system* onto the
|
||
/// accumulator per CSS-COUNTER-STYLES § 3.1.5.
|
||
fn push_numeric_representation(value: i32, system: &[char], accumulator: &mut String) {
|
||
let mut abs_value = handle_negative_value(value, accumulator);
|
||
|
||
// Step 1.
|
||
if abs_value == 0 {
|
||
accumulator.push(system[0]);
|
||
return
|
||
}
|
||
|
||
// Step 2.
|
||
let mut string: SmallVec<[char; 8]> = SmallVec::new();
|
||
while abs_value != 0 {
|
||
// Step 2.1.
|
||
string.push(system[abs_value % system.len()]);
|
||
// Step 2.2.
|
||
abs_value = abs_value / system.len();
|
||
}
|
||
|
||
// Step 3.
|
||
accumulator.extend(string.iter().cloned().rev())
|
||
}
|
||
|
||
/// If the system uses a negative sign, handle negative values per CSS-COUNTER-STYLES § 2.
|
||
///
|
||
/// Returns the absolute value of the counter.
|
||
fn handle_negative_value(value: i32, accumulator: &mut String) -> usize {
|
||
// 3. If the counter value is negative and the counter style uses a negative sign, instead
|
||
// generate an initial representation using the absolute value of the counter value.
|
||
if value < 0 {
|
||
// TODO: Support different negative signs using the 'negative' descriptor.
|
||
// https://drafts.csswg.org/date/2015-07-16/css-counter-styles/#counter-style-negative
|
||
accumulator.push('-');
|
||
value.abs() as usize
|
||
} else {
|
||
value as usize
|
||
}
|
||
}
|